Connectors are used for connecting electric wirings or optical interconnections. These wirings are connected by fitting a pair of two connectors. In an assembly process for mass-production, for example, a plurality of wiring connections are performed. Incomplete fitting of connectors even at one place results in deterioration of quality of a product as well as becomes a cause of an assembly defect. Thus, it is desired to perform fitting operation of connectors precisely and to ensure quality. However, the fitting operation of the connectors is performed by a human work so that a mistake can occurs inevitably.
In Japanese Patent Application Publication No. 2010-113907, for example, an inspection method is disclosed. According to the inspection method, whether or not two connectors are properly fitted is inspected. The connectors are a male connector and a female connector respectively. Engagement portions i.e. locking protrusions are provided on a fitting concave portion of the male connector. Engagement detents i.e. locking arms that are deformable elastically are provided on the female connector. The engagement detents are deformed elastically and go over the engagement portions so as to engage with the engagement portions. Through the engagement, the two connectors become in a properly fitted state. In order to perform the inspection, a holding member and a jig are employed. The holding member holds a male connector. The jig inserts a female connector into the fitting concave portion of the male connector. An optical sensor is provided at the jig. Further, a reference member having a mark is provided movably. The female connector is inserted into the fitting concave portion of the male connector. The mark is detected from a change in the amount of a received light by an optical sensor so that whether or not the two connectors are properly fitted is inspected.
According to the above-described method, whether or not the two connectors are properly fitted is determined by detecting the position of the mark. The dimensions of a plurality of places of the connectors in the fitting direction are involved in setting of the position of the mark. In particular, in order that the above-described engagement portion is engaged with the engagement detent, an allowance dimension is inevitably needed in the fitting direction of the connector.
Recent years, miniaturization of connectors has progressed, and such an allowance dimension becomes smaller as the sizes of connectors become smaller. Further, since dimension tolerances of connectors are also involved in setting of a position of a mark as well as the allowance dimension, setting a position of a mark becomes difficult. As a result, it is difficult to ensure inspection accuracy of a fitted state of the connectors.